In general, a TFT-LCD comprises a bottom plate on which thin film transistors and pixel electrodes are formed, and a top plate on which color filters are constructed. The liquid crystal molecules are filled between the top plate and the bottom plate. During operation, a signal voltage is applied to the TFT, which is the switching element of each pixel unit. The TFT receives a signal voltage and it turns on so that data voltage carrying image information can be applied to the corresponding pixel electrode and to the liquid crystal via the TFT. When the data voltage is applied to the TFT, the orientation of the liquid crystal molecules is changed, thereby altering the optical properties and displaying the image.
There are three process groups, the array process, the cell process and the module assembly process, for forming a thin film transistor liquid crystal display (TFT-LCD). The array process, similar to the semiconductor manufacturing process, is to fabricate thin film transistors on a glass substrate. The cell process joins the arrayed back substrate and the front substrate that is fitted with a color filter. The space between the two substrates is filled with liquid crystal. The module assembly process involves connecting additional components, such as driver integrated circuits and backlight units, to the fabricated glass panel.
When joining the arrayed back substrate and the front substrate, the glue often remains on the surface of the panel, causing a joining mistake. Therefore, a cleaning panel process for removing the glue is performed to avoid the joining mistake.
A scraper with fixed pressure is used in a conventional cleaning panel process for removing the remnant glue. However, only using a single scraper to clean the panel limits the cleaning efficiency. Therefore, a manual cleaning process is always involved in the cleaning panel process. Furthermore, the pressure applied to the scraper is fixed. In other words, there is no buffer apparatus assembled in the scraper, which could otherwise protect the surface of the panel from harm.